Technical Field
Aspects of the present disclosure relate to an image forming apparatus.
Related Art
In an image forming apparatus that employs an electrophotographic method, a belt type image bearer bearing an image contacts a transfer device opposed to the image bearer to form a transfer nip, thereby transferring a toner image onto a recording medium in the transfer nip. In such a configuration, when using a recording medium having a coarse surface or an embossed surface such as Japanese paper (also known as Washi), a pattern of light and dark (unevenness of image density) according to the surface condition of the recording medium appears in an output image. More specifically, toner does not transfer well to such embossed surfaces, in particular, recessed portions of the surface. This inadequate transfer of the toner appears as a pattern of light and dark in the resulting output image. In view of the above, when a superimposed voltage, in which a direct current voltage is superimposed on an alternating current voltage, is applied as a transfer voltage, the superimposed voltage is applied in a transfer direction for a longer time period than in a direction opposite to the transfer direction to improve the transferability.